Support client.table(view) in Python

Cargo.toml

@@ -47,6 +47,7 @@ strip = true
 # These are only respected when `cargo` is invoked from the project root
 [patch.crates-io]
 # simd-adler32 = { git = "https://github.com/mcountryman/simd-adler32.git", rev = "b279034d9eb554c3e5e0af523db044f08d8297ba" }
+protobuf-src = { rev = "1aba500e469f8bdc384a0fe9e69c189fda72e059", git = "https://github.com/MaterializeInc/rust-protobuf-native" }
 perspective-client = { path = "rust/perspective-client" }
 perspective-server = { path = "rust/perspective-server" }
 perspective-js = { path = "rust/perspective-js" }

rust/perspective-python/perspective/tests/table/test_table_view_table.py

@@ -0,0 +1,130 @@
+#  ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
+#  ┃ ██████ ██████ ██████       █      █      █      █      █ █▄  ▀███ █       ┃
+#  ┃ ▄▄▄▄▄█ █▄▄▄▄▄ ▄▄▄▄▄█  ▀▀▀▀▀█▀▀▀▀▀ █ ▀▀▀▀▀█ ████████▌▐███ ███▄  ▀█ █ ▀▀▀▀▀ ┃
+#  ┃ █▀▀▀▀▀ █▀▀▀▀▀ █▀██▀▀ ▄▄▄▄▄ █ ▄▄▄▄▄█ ▄▄▄▄▄█ ████████▌▐███ █████▄   █ ▄▄▄▄▄ ┃
+#  ┃ █      ██████ █  ▀█▄       █ ██████      █      ███▌▐███ ███████▄ █       ┃
+#  ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫
+#  ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
+#  ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
+#  ┃ This file is part of the Perspective library, distributed under the terms ┃
+#  ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
+#  ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
+
+import pandas as pd
+import numpy as np
+from perspective import PerspectiveError
+from datetime import date, datetime
+from pytest import approx, mark, raises
+
+import perspective as psp
+
+client = psp.Server().new_local_client()
+Table = client.table
+
+
+def date_timestamp(date):
+    return int(datetime.combine(date, datetime.min.time()).timestamp()) * 1000
+
+
+def compare_delta(received, expected):
+    """Compare an arrow-serialized row delta by constructing a Table."""
+    tbl = Table(received)
+    assert tbl.view().to_columns() == expected
+
+
+class TestView(object):
+    def test_view_zero(self):
+        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
+        tbl = Table(data)
+        view = tbl.view()
+        tbl2 = Table(view)
+        view2 = tbl2.view()
+        dimms = view2.dimensions()
+        assert dimms["num_view_rows"] == 2
+        assert dimms["num_view_columns"] == 2
+        assert view2.schema() == {"a": "integer", "b": "integer"}
+        assert view2.to_records() == data
+
+    def test_view_one(self):
+        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
+        tbl = Table(data)
+        view = tbl.view(group_by=["a"])
+        tbl2 = Table(view)
+        view2 = tbl2.view()
+
+        dimms = view2.dimensions()
+        assert dimms["num_view_rows"] == 3
+        assert dimms["num_view_columns"] == 3
+        assert view2.schema() == {
+            "a (Group by 1)": "integer",
+            "a": "integer",
+            "b": "integer",
+        }
+
+        assert view2.to_records() == [
+            {"a (Group by 1)": None, "a": 4, "b": 6},
+            {"a (Group by 1)": 1, "a": 1, "b": 2},
+            {"a (Group by 1)": 3, "a": 3, "b": 4},
+        ]
+
+    def test_view_two(self):
+        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
+        tbl = Table(data)
+        view = tbl.view(group_by=["a"], split_by=["b"])
+        tbl2 = Table(view)
+        view2 = tbl2.view()
+        dimms = view2.dimensions()
+        assert dimms["num_view_rows"] == 3
+        assert dimms["num_view_columns"] == 5
+        assert view2.schema() == {
+            "a (Group by 1)": "integer",
+            "2|a": "integer",
+            "2|b": "integer",
+            "4|a": "integer",
+            "4|b": "integer",
+        }
+
+        assert view2.to_records() == [
+            {
+                "a (Group by 1)": None,
+                "2|a": 1,
+                "2|b": 2,
+                "4|a": 3,
+                "4|b": 4,
+            },
+            {
+                "a (Group by 1)": 1,
+                "2|a": 1,
+                "2|b": 2,
+                "4|a": None,
+                "4|b": None,
+            },
+            {
+                "a (Group by 1)": 3,
+                "2|a": None,
+                "2|b": None,
+                "4|a": 3,
+                "4|b": 4,
+            },
+        ]
+
+    def test_view_two_column_only(self):
+        data = [{"a": 1, "b": 2}, {"a": 3, "b": 4}]
+        tbl = Table(data)
+        view = tbl.view(split_by=["b"])
+        tbl2 = Table(view)
+        view2 = tbl2.view()
+        dimms = view2.dimensions()
+        assert dimms["num_view_rows"] == 2
+        assert dimms["num_view_columns"] == 4
+        assert view2.schema() == {
+            "2|a": "integer",
+            "2|b": "integer",
+            "4|a": "integer",
+            "4|b": "integer",
+        }
+
+        assert view2.to_records() == [
+            {"2|a": 1, "2|b": 2, "4|a": None, "4|b": None},
+            {"2|a": None, "2|b": None, "4|a": 3, "4|b": 4},
+        ]

rust/perspective-python/src/client/client_async.rs

@@ -627,7 +627,7 @@ impl AsyncTable {
 #[pyclass]
 #[derive(Clone)]
 pub struct AsyncView {
-    view: Arc<View>,
+    pub(crate) view: Arc<View>,
     _client: AsyncClient,
 }
 

rust/perspective-python/src/client/client_sync.rs

@@ -469,7 +469,7 @@ impl Table {
 /// Perspective conserves memory by relying on a single [`Table`] to power
 /// multiple [`View`]s concurrently.
 #[pyclass(subclass, name = "View", module = "perspective")]
-pub struct View(AsyncView);
+pub struct View(pub(crate) AsyncView);
 
 assert_view_api!(View);
 

rust/perspective-python/src/client/table_data.rs

@@ -70,7 +70,11 @@ pub impl TableData {
         input: Bound<'_, PyAny>,
         format: Option<TableReadFormat>,
     ) -> Result<TableData, PyErr> {
-        if let Some(update) = UpdateData::from_py_partial(&input, format)? {
+        if let Ok(view) = input.downcast::<crate::client::client_async::AsyncView>() {
+            Ok(TableData::View((*view.borrow().view).clone()))
+        } else if let Ok(view) = input.downcast::<crate::client::client_sync::View>() {
+            Ok(TableData::View((*view.borrow().0.view).clone()))
+        } else if let Some(update) = UpdateData::from_py_partial(&input, format)? {
             Ok(TableData::Update(update))
         } else if let Ok(pylist) = input.downcast::<PyList>() {
             let json_module = PyModule::import(input.py(), "json")?;